1. Field Of The Invention
This invention relates to electronic voltmeters.
2. Description Of The Prior Art
Numerous electronic voltmeters are known to the prior art. These electronic voltmeters include digital readouts as well as calibrated light readouts. One form of electronic voltmeter using a calibrated light readout is illustrated in the U.S. Pat No. 3,796,951 to Joseph. Joseph uses a series of light emitting diodes as readouts. U.S. Pat. No. 3,619,574 in the name of Mindheim, U.S. Pat. No. 3,754,121 in the name of Delay, et al, and U.S. Pat. No. 3,825,827 in the name of Tumbush also disclose electronic voltmeters with digital readouts.
The electronic voltmeter of the present invention is particularly suited for use with appliance type electronic equipment, particularly radio receivers, tape recorders, and other audio electronics. In the past, volume unit measurements for such equipment have been made using conventional electromechanical devices such as meters with permanent magnet moving coils, or iron vane movements, or electrostatic movements, and electrodynamometers. Recently, direct digital numerical readouts have also been used to indicate volume unit levels for such equipment.
The prior art approaches to monitoring volume units have several deficiencies. First, mechanical meters monitoring fluctuating signals must be read on the move, and digital readouts indicating fluctuating signals tend to blur several digits. Second, short duration signals are particularly difficult to track using prior art meters. For mechanical meters, response is limited by inertia; for digital readouts, by display time. Furthermore, the conventional mechanical monitor has wear points and is difficult to read at a distance.